In a scenario where you have one of the following special characters in a Reference " \/:*/<>|." HTML5 Designer deployment will fail and show an error message:
You are unable to deploy a workflow that contains references with special characters " \/:*/<>|."
This is an HTML5 Designer specific bug and will be addressed in a future release.
1) Rename the list and remove the special characters, then regenerate the SmartObjects.
2) If the Reference with the error is not needed in the Design you can delete the Reference from the Designer.
3) In Designer, find the Reference that is marked with a ALM tag (Explanation), right-click the Reference and rename by removing the special character.
Also note the following KB: https://help.k2.com/kb000299